Charles e



(Nb Model.)

0. E. SKINNER.

ELECTRICAL DISCHARGE DEVICE.

N0. 571 ,099. Patented Nov. 10, 1896.

ATTORNEY.

win/8858.-

UNITED STATES PATENT OFFICE.

CHARLES E. SKINNER, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THEWESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF SAME PLACE.

ELECTRICAL-DISCHARGE DEVICE.

SPECIFICATION forming part of Letters Patent No. 571,099, dated November10, 1896.

Application filed May 21, 1896. Serial No. 584,208. (No model.)

To all whom, it may concern:

Be it known that 1, CHARLES E. SKINNER, a citizen of the United States,residing in Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement inElectrical-Discharge Devices, (Case No. 694,) of which the following isa specification.

My invention relates to electrical a pparatus,

IO and particularly to such apparatus as embodies separated electrodesbetween which electrical discharges take place.

The object of my invention is to provide an apparatus of this characterwhich will facili- I 5 tate the passage of electrical discharges to sucha degree as will permit the separation of the electrodes to aconsiderable distance,and thus greatly increase the length of the sparkfor a given electromotive force beyond that secured in connection withapparatus heretofore employed.

I have found that if the positive and negative terminals of an electriccircuit be placed in conduct with or in close proximity to a body ofinsulating material, and if one of them be electrically connected with aconducting-body placed upon the opposite side of said insulating-body,the sparking-distance between such electrodes will be several timesgreater than the sparking-distance when the electrodes are separatedmerely by an airspace. This result is secured both with staticdischarges and also when the electrodes are the terminals of circuitssupplied with a dy- 3 5 namo-current. It it well known that a staticdischarge will pass through an air-gap between electrodes which willprevent the passage of a dynamo-current, and this fact has heretoforebeen generally utilized in the construction of lightning-arresters forthe protection of dynamo-circuits and the translating devices fedthereby. It follows, therefore, that the principle embodied in myinvention may be advantageously employed in 5 the construction oflightning-arresters, since it permits of a much wider separation of theelectrodes than has heretofore been possible.

The invention is also applicable for use in connection with generatorsof static electricity, since it afiords means whereby the length of thespark which may be secured from such a machine may be increased toseveral times that which has heretofore been possible.

The invention may be utilized for any other purposes to which it may beadapted, and I therefore do not desire to limit it to any specific use.

It has been found that an electrical discharge between two electrodes isfacilitated by placing such electrodes in contact with a solid insulatedsurface, and this is probably due to the fact that there is a lessintimate contact between the molecules of air and the molecules of thesolid material than there is between the different molecules of the air.By providing a conducting-body at the opposite side of theinsulating-body and connecting the same with one of the electrodes acondenser action results, which apparently serves to repel the moleculesof air on the electrode side from the surface of the insulating-body,

and thus permits of the passage of the discharge along the surface ofthe insulatingbody between the electrodes with much greater facilitythan obtains either when no solid body is present or when only theinsulating-body is employed.

In the accompanying drawing I have illustrated diagrammatically anapparatus embodying my invention, in which- 1 and 2 are two electrodesseparated a considerable distance and placed in contact with one face ofa plate 3 of insulating material. This plate may be of any convenientmaterial and thickness. I have found that glass is a suitable material,although I do not desire to limit my invention in this regard, and thethickness should be suflicient to preclude any puncturing or rupturingof the same when employed in connection with high potentials, and itmust also be thin enough to secure the necessary repulsion of theairmolecules from the face in contact with the electrodes.

4 is a plate of conducting material, which may be of any suitable metaland of any convenient thickness. This plate is located upon the side ofthe insulating plate opposite to that upon which the terminals 1 and 2rest,

and it may conveniently be in the form of a V sheet of metal foil. Ipreferably make this plate or sheet of suflicient length to bridge thespace between the electrodes, but the invention is not limited asregards the length of such plate or sheet. This metal plate or sheet iselectrically connected with the electrode 2, as indicated in thedrawings, by means of a suitable conductor 5. A condenser 6 may beinterposed between the electrode 2 and the plate 4:, if desired, but Ido not regard this as a necessary adjunct. The connection may be madedirectly, as indicated by the broken line '7 The electrodes 1 and 2 areconnected with a source of electrical energy 8, which, as indicated inthe drawing, comprises a dynamo 9 and a transformer 10. This source ofenergy may be a generator of statical electricity, if desired, as willbe readily understood.

If the parts 1 and 2 are the electrodes of a static machine, it isapparent that the length of the spark which may be secured from themachine for laboratory or exhibition purposes will be much longer thanany that it has heretofore been possible to secure.

In case the invention is utilized as a lightning-arrester it will beunderstood that one of the electrodes will be connected to the line tobe protected and the other will be grounded.

I do not desire to limit my invention to the particular form ofapparatus shown and described, since it may be variously modified andadapted to particular purposes wherever it may be found useful withoutdeparting from the spirit and scope of my invention.

I claim as my invention- 1. An electrical-discharge device comprising anon-conducting body having a comparatively smooth surface, a pair ofseparated electrodes located in close proximity thereto, and means forrepelling the air from said surface whereby the passage of electricaldischarges between the electrodes is facilitated.

2. An electrical-discharge device comprising a non-conducting bodyhaving a conducting-coating upon one face and two electrodes in contactwith the other face one of which is electrically connected with theconductingcoating.

3. An electrical-discharge device comprising two separated electrodes, abody of conducting material electrically connected with one of saidelectrodes, and a body of non-con ducting material interposed betweensaid electrodes and said body of conducting material.

4:. An electrical-discharge device comprising an elongated body ofnon-conductin g material, an elongated body of metal in close proximityto one side of the non-conducting body, electrodes in engagement withthe other side, one of which is electrically connected with said body ofmetal.

5. An electrical-discharge device comprising a non-conductingplate, asheet of metal upon one side of the same, a pair of electrodes upon theother side and an electrical connection between one of said electrodesvand said metal sheet.

6. An electrical-discharge device having widely-separated electrodes incontact with one side of a non-conducting body, a conducting-body of alength equal to or greater than the distance between said electrodes andlocated at the opposite side of said non-conducting body andelectrically connected with one of said electrodes.

In testimony whereof I have hereunto subscribed my name this 18th day ofMarch, 1896.

CHARLES E. SKINNER.

\Vitnesses:

WEsLEY' G. CARR, HUBERT C. TENER.

